基于动捕对仿人采摘机械臂运动学分析与仿真

Kinematics Analysis and Simulation of Humanoid Picking Robot Arm Based on Motion Capture

通过三维光学动作捕捉实验采集了人体上肢完成采摘动作时上肢各关节角度的变化及各关节的点位数据,对上肢进行受力分析并利用MatLab编程获得力矩的变化情况。将上肢划分为3个关节7自由度的刚体模型,利用Robotics工具箱建立7自由度的仿人采摘机械臂,并通过D-H方法建立各连杆坐标系写出各连杆参数进行逆运动学分析,求解出机械臂7个关节角度值。由于存在冗余自由度使得逆解结果不唯一,因此提出了“最小能量法”选取最优采摘路径。对最优采摘路径进行五次多项式插值仿真各关节的角度、角速度及角加速度的变化,最后根据各关节的活动度进行末端执行器工作空间的分析。结果表明:“最小能量法”选取的最优解使仿人采摘机械臂在采摘点已知情况下能选择最优的路径进行采摘,整个采摘过程稳定。研究结果为仿人机器人采摘机械臂的运动控制和轨迹优化奠定了基础。

Through the 3D optical motion capture experiment,the changes of the angle of each joint of the upper limb and the point position data of each joint were collected when the human upper limb completed the picking action.The force analysis of the upper limb was carried out and the torque changes were obtained by using MATLAB programming.The upper limb is divided into a rigid body model with three joints and seven degrees of freedom.The robot toolbox is used to build a humanoid manipulator with seven degrees of freedom.The D-H method is used to establish the coordinate system of each connecting rod to write out the parameters of each connecting rod for inverse kinematics analysis,and the angle values of the seven joints of the robot arm are solved.Due to the existence of redundant degrees of freedom,the inverse solution result is not unique,so this paper proposes the minimum energy method to select the optimal picking path.The changes of angle,angular velocity and angular acceleration of each joint were simulated by quintic polynomial interpolation for the optimal picking path.Finally,the end-effector workspace was analyzed according to the degree of motion of each joint.Results show that the minimum energy method to select the optimal solution of the humanoid robot arm in picking the condition of known points can choose the optimal path for picking,through the joint trajectory planning simulation result,the whole process of picking stable,picked the results for the humanoid robot manipulator motion control and path optimization laid a solid foundation.